JPS62270991A - Display unit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Summary] In a display device that displays display information pixel by pixel by rask scanning, by switching the period etc. of the horizontal synchronizing signal according to the 5 display modes. , which allows easy switching between landscape and portrait display.

[Industrial application field]

The present invention relates to a bitmap type display device used as an output device for computer systems and the like.

For example, display information such as characters given from a computer in the form of a code is converted into a dot matrix pattern by a character generator, each dot (pixel) is made to correspond to a coordinate on the display screen, and the dot data is - After writing to the image memory, the data is sequentially read out and displayed on the display section.

CRTs, which are the same as television picture tubes, have been used as display parts for a long time.
Many display screens are used horizontally, and are used to display one drawing or the like.

However, in display devices used as word processors, because documents are often written horizontally on vertically long paper, devices with two vertically long display surfaces have come to be used.

At this time, it is desirable to be able to easily switch between landscape display and portrait display on the same display surface.

[Conventional technology]

2. Description of the Related Art There is a known device in which a display unit such as a CRT is mechanically rotated to switch between vertical display and horizontal display.

[Problem that the invention seeks to solve]

The display device having the above configuration has a problem that it has a complicated structure, which hinders cost reduction, and a problem that it cannot be used for real-time processing because switching takes time.

That is, an object of the present invention is to provide an inexpensive display device that can instantaneously switch between portrait display and landscape display.

[Means for solving problems]

The display device according to the present invention is as shown in the principle diagram of FIG.

and an image memory 1 that stores display information in pixel units in correspondence with display positions.

A signal generating section 2 that generates a horizontal synchronizing signal H3, a vertical synchronizing signal VS, and a blanking signal BS at predetermined timings.
and.

The values of several sets of parameters that determine the timing are set in advance (setting section 3).

It is provided with a selection section 4 that selects the value of the parameter according to the display mode from the set of values set above.

[Effect]

For example, the paper size for number 4 in row A is 210mm x 297mm.
mm, and when the dot density is 10 dots/mm, this is expressed in number of dots as 2100 dots x 297
There are 0 dots.

When displaying this vertically, a horizontal synchronization signal is generated every time the clock signal is counted, for example, 2600 times, and a vertical Generates a synchronization signal.

In addition, in the case of horizontally long display, a horizontal synchronization signal is similarly generated every time the clock signal is counted, for example, 3700 times, and a vertical synchronization signal is generated every time the horizontal synchronization signal is counted, for example, 2130 times.

There are also optimal timings for each blanking signal.

Therefore, by presetting several sets of parameter values that determine the timing of each of these signals in the setting section 3, and selecting parameters according to the display mode from among these and supplying them to the signal generating section 2. , which allows easy switching between portrait and landscape display.

〔Example〕

FIG. 2 is a configuration diagram of the embodiment, and in addition to the symbols explained in FIG.
7 is a horizontal deflection circuit, and 8 is a vertical deflection circuit.

9 is a video signal amplification circuit, and 10 is a CRT.

Further, the vertical deflection circuit 8 includes a counter 81, a DA converter 82, and an amplifier 83.

Display information such as characters is given from the host device in the form of a code via the interface control circuit 5.

The characters are converted into a dot matrix pattern by the character generator 6 and made to correspond to the coordinates on the two display surfaces.

The data is written into the image memory 1 as bit data for each pixel.

The selection unit 4 selects parameter values from the setting unit 3 according to the display mode specified by the host device and sends the selected values to the signal generation unit 2.
give to

When the display starts, the signal generating section 2 counts the clock signals and generates a horizontal synchronizing signal (Is) and a horizontal blanking signal HBS at timings determined by given parameters.

At the same time, the signal generator 2 counts the horizontal synchronization signal) Is,
A vertical synchronizing signal VS and a vertical blanking signal VBS are generated with timings determined by given parameters.

The horizontal blanking signal HBS and vertical blanking signal VBS generated by the signal generating section 2 are applied to the image memory 1 and used as read control signals.

A horizontal synchronizing signal 1 (S) is given to the horizontal deflection circuit 7 and used to generate a horizontal deflection current.

Further, a horizontal synchronizing signal 1 (S) and a vertical synchronizing signal VS are given to the vertical deflection circuit, and are used to generate a vertical deflection current. That is, the horizontal synchronizing signal H5 and the vertical synchronizing signal vS are respectively applied to the counter 81. The output of each bit of the counter 81 is applied to an input terminal and a reset terminal, and is converted into a stepped analog signal by a DA converter 82, and the output is amplified by an amplifier 83 to generate a vertical deflection signal.

In the embodiment, the period of the horizontal synchronizing signal is changed depending on the type of 8 display mode, but the period of the clock signal is constant. Therefore, the horizontal deflection current increases in proportion to the period of the horizontal synchronization signal. Similarly, the vertical deflection current also increases proportionally due to the vertical display dots.

Therefore, it is not necessary to provide the horizontal deflection circuit 7 and the vertical deflection circuit 8 with a special function for adjusting the display amplitude when switching between the two display modes.

〔Effect of the invention〕

As explained above, the display device of the present invention can instantaneously switch between portrait display and landscape display with an inexpensive configuration.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the principle of the present invention. FIG. 2 is a configuration diagram of the embodiment. In the figure. 1 is an image memory, 2 is a signal generation section.

Claims (1)

[Scope of Claims] An image memory (1) that stores display information in correspondence with the display position on a pixel basis, and a signal generator that generates a horizontal synchronization signal, a vertical synchronization signal, and a blanking signal at predetermined timings. a setting section (3) for presetting a parameter value for determining the timing; and a selection section (4) for selecting a parameter value according to a display mode from the set values. A display device characterized by: